1. Field of the Invention
The present invention relates to a technology for controlling a radiation direction of an omni-directional antenna attached to a terminal configuring a mobile communication network, wireless communication network, or sensor network.
2. Description of the Related Art
Generally, a terminal used for mobile communication, wireless communication, and a sensor network uses a small omni-directional antenna to perform the communication. The omni-directional antenna is capable of radiating radio waves with a constant intensity in all directions along a horizontal plane. The omni-directional antenna has a characteristic of radiating radio waves within a specific beam width when installed vertically to a ground surface. Therefore, when the omni-directional antenna or a terminal including the omni-directional antenna is not vertical to the ground surface, the radiation direction of the omni-directional antenna may lose omni-directionality.
FIG. 1 illustrates a diagram showing a radiation pattern of an omni-directional antenna 102 installed vertically to a ground surface according to a related art.
According to FIG. 1, the omni-directional antenna 102 may be attached to a terminal 101. Here, the terminal 101 may be installed on a ground surface 103. That is, the omni-directional antenna 102 may form a right angle with respect to the ground surface 103. Accordingly, a radiation direction 104 of the omni-directional antenna may be horizontal to the ground surface 103. When the radiation direction 104 is formed to be horizontal to the ground surface 103, the omni-directional antenna 102 may radiate radio waves with a constant intensity along the ground surface 103, thereby achieving omni-directionality.
FIG. 2 illustrates a diagram showing a radiation pattern of an omni-directional antenna 202 installed on an inclined surface 201 according to a related art.
According to FIG. 2, the terminal attached with the omni-directional antenna 202 may be installed on the inclined surface 201. Accordingly, a radiation direction 203 of the omni-directional antenna 202 may be sloped with respect to the ground surface 204.
When the radiation direction of the omni-directional antenna is inclined, an amount wave gain in the horizontal direction may be reduced while a number of reflected waves may be increased by the ground surface. Consequently, the omni-directionality of the omni-directional antenna may be reduced, thereby reducing the performance of the omni-directional antenna.
Accordingly, there is a desire for a new scheme for minimizing reduction of the performance of the omni-directional antenna even though the omni-directional antenna is installed on an inclined surface.